Bioinspired Photoactive Cu-Halide Coordination Polymers for Reduction Activation and Oxygen Conversion.

Natural copper oxygenases provide fundamental principles for catalytic oxidation with kinetically inert molecular oxygen, but it remains a marked challenge to mimic both their structure and function in an entity. Inspired by the CuA enzymatic sites, herein we report two new photoactive binuclear copper-iodine- and bisbenzimidazole-comodified coordination polymers to reproduce the natural oxo-functionalization repertoire in a unique photocatalytic pathway. Under light irradiation, the Cu-halide coordination polymers effectively reduce NHP esters and complete oxygen reduction activation via photoinduced electron transfer for the aerobic oxidative coupling of hydroquinone with terminal alkynes, affording hydroxyl-functionalized ketones with high efficiency and selectivity. This supramolecular approach to developing bioinspired artificial oxygenases that merge transition metal- and photocatalysis supplies a new way to fabricate distinctive photocatalysts with desirable catalytic performances and controllable precise active sites.

KG4NH: A Comprehensive Knowledge Graph for Question Answering in Dietary Nutrition and Human Health.

It is commonly known that food nutrition is closely related to human health. The complex interactions between food nutrients and diseases, influenced by gut microbial metabolism, present challenges in systematizing and practically applying knowledge. To address this, we propose a method for extracting triples from a vast amount of literature, which is used to construct a comprehensive knowledge graph on nutrition and human health. Concurrently, we develop a query-based question answering system over our knowledge graph, proficiently addressing three types of questions. The results show that our proposed model outperforms other state-of-art methods, achieving a precision of 0.92, a recall of 0.81, and an F1 score of 0.86 in the nutrition and disease relation extraction task. Meanwhile, our question answering system achieves an accuracy of 0.68 and an F1 score of 0.61 on our benchmark dataset, showcasing competitiveness in practical scenarios. Furthermore, we design five independent experiments to assess the quality of the data structure in the knowledge graph, ensuring results characterized by high accuracy and interpretability. In conclusion, the construction of our knowledge graph shows significant promise in facilitating diet recommendations, enhancing patient care applications, and informing decision-making in clinical research.

Photocatalytic C(sp3)-H bond functionalization by Cu(I) halide cluster-mediated O2 activation.

Photocatalytic C-H bond activation is a challenging approach to selectively functionalize C(sp3)-H bonds with dioxygen under mild conditions. Herein, by merging transition metal- and photo-catalysis, photoactive Cu(I)-halide(X) (X = Cl, Br, I) clusters are employed to effectively catalyse the selective monooxygenation and C-C oxidative cross-coupling of C(sp3)-H bonds with unreactive O2 upon light irradiation. This modern protocol promises a photoinduced SET process between Cu(I)-clusters and O2, and possibly forms Cu(II)-O2˙- species for abstracting the H-atom from the C(sp3)-H bond. This process produces alkyl radicals to react with -OOH or nucleophiles for oxidation or cross-coupling products, advancing the Cu(I)-cluster mediated photoredox catalysis toward functional fine chemicals with pursued selectivity.

Binding of Dual-Function Hybridized Metal-Organic Capsules to Enzymes for Cascade Catalysis.

The combination of chemo- and biocatalysis for multistep syntheses provides attractive advantages in terms of evolvability, promiscuity, and sustainability striving for desirable catalytic performance. Through the encapsulation of flavin analogues by both NADH and heme mimics codecorated heteroleptic metal-organic capsules, herein, we report a progressive host-guest strategy to imitate cytochrome P450s catalysis for cascade oxidative coupling catalysis. Besides the construction of stable dual-function metal-organic capsules and the modification of cofactor-decorated capsules at the domain of enzymes, this supramolecular strategy involves multistage directional electron flow, affording reactive ferric peroxide species for inducing oxygenation. Under light irradiation, the metal-organic capsule selectively converts stilbene to oxidative coupling products (including 2-oxo-1,2-diphenylethyl formate, 2-alkoxy-1,2-diphenylethanone) in tandem with enzymatic reactions respectively, at the domain of natural enzymes. The ingenious combination of capsules and enzymes with the in situ-regenerated capsule-loaded NADH cofactor promises non-native coupling reactions by forming regional cooperation and division. This abiotic-biotic conjugated host-guest strategy is conducive to the de novo creation of multifunctional components approaching active enzymatic sites for reinforced matter and energy transporting, demonstrating a key role of multicomponent supramolecular catalysts for one-pot integrated catalytic conversions.

A Metal-Organic Framework as a Multiphoton Excitation Regulator for the Activation of Inert C(sp3 )-H Bonds and Oxygen.

The activation and oxidization of inert C(sp3 )-H bonds into value-added chemicals affords attractively economic and ecological benefits as well as central challenge in modern chemistry. Inspired by the natural enzymatic transformation, herein, we report a new multiphoton excitation approach to activate the inert C(sp3 )-H bonds and oxygen by integrating the photoinduced electron transfer (PET), ligand-to-metal charge transfer (LMCT) and hydrogen atom transfer (HAT) events together into one metal-organic framework. The well-modified nicotinamide adenine dinucleotide (NAD+ ) mimics oxidized CeIII -OEt moieties to generate CeIV -OEt chromophore and its reduced state mimics NAD. via PET. The in situ formed CeIV -OEt moiety triggers a LMCT excitation to form the alkoxy radical EtO. , abstracts a hydrogen atom from the C(sp3 )-H bond, accompanying the recovery of CeIII -OEt and the formation of alkyl radicals. The formed NAD. activates oxygen to regenerate the NAD+ for next recycle, wherein, the activated oxygen species interacts with the intermediates for the oxidization functionalization, paving a catalytic avenue for developing scalable and sustainable synthetic strategy.

A host-guest semibiological photosynthesis system coupling artificial and natural enzymes for solar alcohol splitting.

Development of a versatile, sustainable and efficient photosynthesis system that integrates intricate catalytic networks and energy modules at the same location is of considerable future value to energy transformation. In the present study, we develop a coenzyme-mediated supramolecular host-guest semibiological system that combines artificial and enzymatic catalysis for photocatalytic hydrogen evolution from alcohol dehydrogenation. This approach involves modification of the microenvironment of a dithiolene-embedded metal-organic cage to trap an organic dye and NADH molecule simultaneously, serving as a hydrogenase analogue to induce effective proton reduction inside the artificial host. This abiotic photocatalytic system is further embedded into the pocket of the alcohol dehydrogenase to couple enzymatic alcohol dehydrogenation. This host-guest approach allows in situ regeneration of NAD+/NADH couple to transfer protons and electrons between the two catalytic cycles, thereby paving a unique avenue for a synergic combination of abiotic and biotic synthetic sequences for photocatalytic fuel and chemical transformation.

A host-guest approach to combining enzymatic and artificial catalysis for catalyzing biomimetic monooxygenation.

Direct transfer of protons and electrons between two tandem reactions is still a great challenge, because overall reaction kinetics is seriously affected by diffusion rate of the proton and electron carriers. We herein report a host-guest supramolecular strategy based on the incorporation of NADH mimics onto the surface of a metal-organic capsule to encapsulate flavin analogues for catalytic biomimetic monooxygenations in conjunction with enzymes. Coupling an artificial catalysis and a natural enzymatic catalysis in the pocket of an enzyme, this host-guest catalyst-enzyme system allows direct proton and electron transport between two catalytic processes via NADH mimics for the monooxygenation of both cyclobutanones and thioethers. This host-guest approach, which involves the direct coupling of abiotic and biotic catalysts via a NADH-containing host, is quite promising compared to normal catalyst-enzyme systems, as it offers the key advantages of supramolecular catalysis in integrated chemical and biological synthetic sequences.

Negatively charged metal-organic hosts with cobalt dithiolene species: improving PET processes for light-driven proton reduction through host-guest electrostatic interactions.

By incorporating 1,2-benzenedithiol as a chelator to construct cobalt dithiolene species, two negatively charged redox-active metal-organic hosts were obtained. By taking advantage of electrostatic interactions, cationic Ru-based photosensitizers were constrained to improve photoinduced electron transfer processes for efficient photocatalytic proton reduction.